Sphaerechinus granularis is a sea urchin of up to 12 cm in diameter. It is globular,
slightly top-flattened. The test is dark purple and spines may be purple too but very often with white tips
or even entirely white. It often covers itself with algae or shell remains held by its tube-feet
and pedicellariae. It feeds on algae grazed on rock surface. It lives on rocks, boulders and also on Maerl,
a calcareous algae.
It is found from surface to 100 m deep in the Atlantic Ocean down to Cape Verdes, in the English Channel and the Mediterranean Sea.
(source : European Register of Marine Species)
Tube foot : Tube-shaped element ending by a sucker-disc used to attach to subtratum or to bring food
particles into the mouth.
Pedicellariae : Minute jawed elements of sea urchins and starfish used to clean body surface and as defensive means.
Top Photo :
© Wilfried Bay-Nouailhat. Published with author's kind permission :
Sphaerechinus granularis, Baie de Concarneau, South-Brittany, West of France. Depth 8 meters.
Text : Anne Bay-Nouailhat © 2005-2017.
Translation : Anne Bay-Nouailhat © 2007-2017.